Field of the Invention
Various embodiments of the present invention relate to an electronic device, and more particularly to a semiconductor memory device and a driving method thereof.
Description of the Related Art
Semiconductor disk devices are used instead of conventional hard disc drives (HDDs) that are slow, heavy, big and very noisy due to a rotating physical disc.
Semiconductor memory devices are embodied using semiconductors such as silicon (Si), Germanium (Ge), gallium arsenide (GaAs), indium phosphide (InP), etc. The semiconductor memory devices may be divided into volatile memory devices and nonvolatile memory devices.
The volatile memory devices may lose data stored therein if a power supply is blocked. The volatile memory devices include a Static RAM (SRAM), a Dynamic RAM (DRAM), a Synchronous DRAM (SDRAM), etc. The nonvolatile memory devices may retain data stored therein even when not powered. The nonvolatile memory devices include a Read Only Memory (ROM), Programmable ROM (PROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable and a Programmable ROM (EEPROM), a flash memory, a Phase-change RAM (PRAM), a Magnetic RAM (MRAM), a Resistive RAM (RRAM), a Ferroelectric RAM (FRAM), etc. The flash memory may be a NOR type or a NAND type.
Recently, a research on a three-dimensional (3D) semiconductor memory device, in which cell strings are two-dimensionally arranged, is in progress to increase the degree of integration.